Can anyone help identify these items?

Hello, I am new here and I found you because I am looking for help identifying some items left to me by my Uncle that have quite a bit of sentimental value. My Uncle joined the Fleet Air Arm in the late 40’s and became an Aircraft Artificer. He left in the mid 50’s and went to work at Westland although during his time in the RN I do know he worked on both fixed and rotary wing aircraft.

He was my friend, mentor and hero.

He left me some stuff when he died and amongst them are the following items that I am sure are aviation related but I am not sure exactly what aircraft they belong to. I did post some questions on another (non aviation) forum and ZRX61 was helpful with some other items but I am still stumped by these:

First is a ladder which I believe is to access an aircraft but I would love know what type of aircraft.

Next a couple of gauges that look to me like the sort of thing an apprentice might make. It has been suggested that they are for setting stop clearances and one could be for a Rolls turbo prop engine. As a non aviation guy I have no idea what a stop clearance is?

Finally I am not sure what this peg spanner is for although the paint on it seems similar to the remnants of paint on a Fairey Firefly Oleo oil plug wrench that I also have from my Uncle.

Any light that anyone can shed on these items would be absolutely fantastic because, as stated above, they have great sentimental value to me but I have very little aviation knowledge.

Thanks.